The ODR class gathers all information and coordinates the running of the
main fitting routine.

Members of instances of the ODR class have the same names as the arguments
to the initialization routine.

Parameters:

data : Data class instance

instance of the Data class

model : Model class instance

instance of the Model class

Other Parameters:

beta0 : array_like of rank-1

a rank-1 sequence of initial parameter values. Optional if
model provides an “estimate” function to estimate these values.

delta0 : array_like of floats of rank-1, optional

a (double-precision) float array to hold the initial values of
the errors in the input variables. Must be same shape as data.x

ifixb : array_like of ints of rank-1, optional

sequence of integers with the same length as beta0 that determines
which parameters are held fixed. A value of 0 fixes the parameter,
a value > 0 makes the parameter free.

ifixx : array_like of ints with same shape as data.x, optional

an array of integers with the same shape as data.x that determines
which input observations are treated as fixed. One can use a sequence
of length m (the dimensionality of the input observations) to fix some
dimensions for all observations. A value of 0 fixes the observation,
a value > 0 makes it free.

job : int, optional

an integer telling ODRPACK what tasks to perform. See p. 31 of the
ODRPACK User’s Guide if you absolutely must set the value here. Use the
method set_job post-initialization for a more readable interface.

iprint : int, optional

an integer telling ODRPACK what to print. See pp. 33-34 of the
ODRPACK User’s Guide if you absolutely must set the value here. Use the
method set_iprint post-initialization for a more readable interface.

errfile : str, optional

string with the filename to print ODRPACK errors to. Do Not Open
This File Yourself!

rptfile : str, optional

string with the filename to print ODRPACK summaries to. Do Not
Open This File Yourself!

ndigit : int, optional

integer specifying the number of reliable digits in the computation
of the function.

taufac : float, optional

float specifying the initial trust region. The default value is 1.
The initial trust region is equal to taufac times the length of the
first computed Gauss-Newton step. taufac must be less than 1.

sstol : float, optional

float specifying the tolerance for convergence based on the relative
change in the sum-of-squares. The default value is eps**(1/2) where eps
is the smallest value such that 1 + eps > 1 for double precision
computation on the machine. sstol must be less than 1.

partol : float, optional

float specifying the tolerance for convergence based on the relative
change in the estimated parameters. The default value is eps**(2/3) for
explicit models and eps**(1/3) for implicit models. partol must be less
than 1.

maxit : int, optional

integer specifying the maximum number of iterations to perform. For
first runs, maxit is the total number of iterations performed and
defaults to 50. For restarts, maxit is the number of additional
iterations to perform and defaults to 10.

array (stpd.shape==data.x.shape or stpd.shape==(m,)) of relative
step sizes to compute finite difference derivatives wrt the input
variable errors. If stpd is a rank-1 array with length m (the
dimensionality of the input variable), then the values are broadcast to
all observations.

sclb : array_like, optional

sequence (len(stpb)==len(beta0)) of scaling factors for the
parameters. The purpose of these scaling factors are to scale all of
the parameters to around unity. Normally appropriate scaling factors
are computed if this argument is not specified. Specify them yourself
if the automatic procedure goes awry.

scld : array_like, optional

array (scld.shape == data.x.shape or scld.shape == (m,)) of scaling
factors for the errors in the input variables. Again, these factors
are automatically computed if you do not provide them. If scld.shape ==
(m,), then the scaling factors are broadcast to all observations.

work : ndarray, optional

array to hold the double-valued working data for ODRPACK. When
restarting, takes the value of self.output.work.

iwork : ndarray, optional

array to hold the integer-valued working data for ODRPACK. When
restarting, takes the value of self.output.iwork.

Attributes

data

(Data) The data for this fit

model

(Model) The model used in fit

output

(Output) An instance if the Output class containing all of the returned data from an invocation of ODR.run() or ODR.restart()